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Electrolysis and Redox reaction prediction questions - Help?

Hello everyone. I have a few questions regarding work I was assigned for one of my classes.

Predicting Redox Reactions
Q1. For each situation, list the entities present, write the half reactions and overall equations then predict whether it is spontaneous or not.

If I had two aqueous ionic solids in a basic solution, I would split the metal and the non-metal into their respective ions in aqueous form? This also stays true for any poly-atomic ions, correct? Then, I use a standard reduction table such as [url=http://hyperphysics.phy-astr.gsu.edu/hbase/tables/electpot.html]this[/url] to get the half reactions. Checking whether it is spontaneous or not requires me making sure the strongest oxidization agent is below (in the case of this table) of the strongest reducing agent as well? Finally, is water, hydrogen and hydroxide present because it is in a basic solution? Are they included in the half reactions?

Electrolysis
Q2. A power supply is connected to force any reactions to occur. What are the reactions at the cathode, anode and overall cell? My two electrodes are tin which are in an
aqueous solution of two ionic compounds. One has a polyatomic ion.

Firstly, I should split the compounds into their aqueous ions and find which one is the strongest oxidizing and reducing, right? Do I need to include water/hydrogen/hydroxide in my half reactions? Since it is an electrolysis question, the SRA should be below the SOA for the table I provided? If I get a minimum potential difference that is negative, have I done something wrong with the calculation for this kind of cell?
*Note: I found what I believe are my SRA and SOA and put my SRA as my anode for the calculation: Er of the cell = Ecathode - Eanode
, but my SOA is below my SRA (spontaneous I believe). Is that my error and can one of my half reactions include an element that isn't present in the solution?
Ex: ClO4-(aq) + H2O(l) + 2e- -> ClO3-(aq) + 2OH-(aq) when a chlorate/chlorine molecule is not in solution

Thanks in advance.
I can provide the actual elements and compounds if necessary, but I would prefer a few methods or tips anyone can provide.

June 3, 2014

2 Comments • Newest first

Pheonixsblaze

[quote=Castrius]Whatever oxidizes is the anode and whatever Reduces is the Cathode. I would post my notes but im too lazy since schools already out for me.[/quote]
You are lucky, I have about 2 weeks left . For electrolysis, does it matter if the reaction is spontaneous or not?

[quote=Marth]the mitochondria is the powerhouse of the cell[/quote]Is the matrix your favorite part?

@Kamikazedes No help?

Reply June 3, 2014 - edited
Castrius

Whatever oxidizes is the anode and whatever Reduces is the Cathode. I would post my notes but im too lazy since schools already out for me.

Reply June 3, 2014 - edited